The relation between molecular dynamics and configurational entropy in room temperature ionic liquids: Test of Adam–Gibbs model.

In this communication, the Adam–Gibbs model connecting molecular dynamics with configurational entropy is tested for the first time for ionic liquids. For this purpose, we investigate simultaneously the shear viscosity η and configurational entropy Sc of an aprotic ionic liquid: 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIm TFSI). Comparing the Sc data obtained by the combination of Vogel–Fulcher–Tammann and Adam–Gibbs equations to the Sc points determined directly from the calorimetric experiment, good agreement is found in the entire supercooled liquid region. These results indicate the validity of the Adam–Gibbs model in materials with electrostatic interactions being dominated. These important findings not only generalize the applications of the Adam–Gibbs theory but also provide an opportunity to gain insight into the relationship between thermodynamics and molecular dynamics in ionic liquids. [ABSTRACT FROM AUTHOR]